OSCAR-11 Report

OSCAR-11 REPORT
15 August 2005
OSCAR-11 is back! I received the good news, on Saturday morning, while at
the AMSAT-UK Colloquium. This was entirely unexpected! On Sunday morning
Bob G4VRC played me a recording of an early morning pass received that day.
During the period 21 July to 14 August 2005 consistent signals have been
heard from 30 July to 08 August. Signals seem to be weaker than usual,
confirmed by the many reports received. However,since I last heard the
satellite on 30 April, I've reinstalled my antennas , which makes
comparisons difficult.
Many thanks for all the recent reports of OSCAR-11 including those
from KB2M (who heard it first), VK6XH, KU7Z, HK7MKE, KA2UPW, JE9PEL,
G1OCN, HB9SKA and G8OQM.
All the analogue telemetry channels, 0 to 59 are zero, ie they have
failed. The status channels 60 to 67 are still working. One bit in
channel 62, DSR mode, has changed from WRITE to READ. DSR is the Digital
Store & Readout experiment. This could be significant if the experiment
is still drawing current, but the other status bit indicates that it is
switched OFF.
The on-board clock is now showing a very large error. It has lost
approximately 19 days since 30 April. During the recent data collection
period, the clock error has been changing at a decreasing rate. The size
of the clock error and the rate at which it is changing is similar to the
duration of the solar eclipse periods. This suggests that the clock might
have been switching OFF during eclipses.
The eclipses have now ended, and the satellite should be in continuous
sunlight for the remainder of this year, and well into next year. This
should help the satellite to continue transmitting, although continuous
sunlight can cause problems due to excessive temperatures.
If the watchdog timer is still operating on a 20 day cycle, ie.
approximately ten days ON followed by 10 days OFF, then the VHF beacon
should resume transmissions around 18 August.
The Beacon frequencies are -
VHF 145.826 MHz. AFSK FM ASCII Telemetry
UHF 435.025 MHz. OFF
S-band 2401.5 MHz. OFF
Listeners to OSCAR-11 may be interested in visiting my website which
contains an archive of news & telemetry data. It also contains details
about using a soundcard or hardware demodulators for data capture. There
is software for capturing data, and decoding ASCII telemetry. The URL is
www.users.zetnet.co.uk/clivew/
If you place this bulletin on a terrestrial packet network, please
use the bulletin identifier $BID:U2RPT112.CWV, to prevent duplication.
73 Clive G3CWV g3cwv@amsat.org
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Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
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